It's a Triplett 3444 that has been enhanced.
This tester uses regulated power sources for the bias, plate, & screen voltages, as well as modified operating & testing procedures.
Filament voltage is also controlled.
Tubes are tested in accordance with the manufacturer's specifications; measurements closely align with a laboratory tester built to rigorously measure vacuum tube characteristics.
Tubes can be accurately matched for gm & plate current at the manufacturer's specified test points or at other specified test points.
***** This tester was prepared by Mr. Paul Hart of Roswell, GA
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Industry Bogey transconductance = 5500|5500 µmhos
Industry Bogey plate current = 11.0|11.0mA
Results =5200|4900 µmhos ~ |mA